Draft gear



March 16 1926.

DRAFT GEAR 2 Sheets-Sheet 1` Filed March 25, 1923 March 16 1926.1,576,722 W H. COTTON DRAFT GEAR Filed March 23, 1923 2 Sheets-Sheet 2Patented Mar. 16, 1926.

y UNITED stares WALTER H. common, oncnronso, ILM-ners, Assrenon lroeinen nnaF'ronnR-coi,

Aconnonnmionror ILLINOIS. i

DRAFT ',GEAB.-

Application filed March 23,1923. .Serial No. ,627,073.

To all 'whom t 'may concern:

Beit :known ,that I, NAL'rnRl-I. 1COTTON, a citizen Aof -the UnitedStates, ,resident of Chicago, county ,of Cook, and State .of Illinois,,have ,invented .certain new ,and use- .ful Improvements in Dra-ftGears, of which the followingis a specification,.and which areillustrated in the accompanying draw`r ings, forming apart thereof.

The invention relates to :draft gears or shock-.absorbing devices foruse in connecrtion with railway cars; and has for its 4olo- .jects tosecure simplicity o f Iconstruction and application, together. with highefficienc7 and .long range of compressive movement. c

The invention consists in a device as hereinafter described, and asillustratedin ,the `aecompanying drawings, `in which Q Fig. 'f1 is `adetail plan view,.partlyin section, of the -underframing .of ,a .car andof .the improved gear;

Figs. 2 .and 3 vare .details ofwedging elements forming parts of thegear; 1 v U Fig. 4 is a View -i-n ,perspective .of a fr1ction plate`forming a part ofthe ,gearg Fig. ,5 is ,a View in perspective of one-o-f the fgllowers forming a part-.of the gear;

6 isa view similar to Fig. 1, showthegear under compression; and

Fig. ,7 is a view similar toFig. ,1,show1ng a v,Iriodied -form ofconstruction.

The ,usual center sills-of a car, which may be .of any desired form Iofconstruction, vare ,shown at 10, 11; a pair of .draft lugs applied,respectively, ,to the two sills, at 1 2, 13, and vva pair of buffnglugssimilarly lapplied, lat 14, 15. 'Elie butt of a .coupler 1s shown at1,7, and the coupler extensionfor volte at 18, ,this element :taking theform of a :loop Vfor inclosing the gear.

Themlraft gear comprises :front and rear followers 19 20, which engage,respectively, the draft ,and buffi-ng lugs, the end .of `,the couplerbutt andthe rear end ofthe yoke. The inner facesgof the followers ,arebeveled inwardly from their side margins `toward .the center of thegear, :to form wedging faces as shown. -K c A .pall-r of triangularwedge-blocks `21, 24, .are seated .against the inclinedfaces of .thefollower 19, aand :a similar pair of blocks 423, v26, are seatedAagainst the inclined faces of the follower 20. A pair of triangularfrfotonehlocksi), fare seated against and cooperate with fthe oppositewedging faces of the blocks 21, 24,"and ,a similarcpairioffriction-blocks 28, 39, cooperate in like man- .vner with .the blocks.23, 26. `A pairy of ,.wedgefblocksv22, 25,',are interposed between ,andcooperate, respectively, with the fbloclrs 28, and with the blocks 29,30.

c The several llwed,ge-blocks 21 to r26 are similarrin form, one of thembeing shown in F.ig.12.l The several blocks 27 to .30V are csimilar in`form, .one 4of l,them being. lrepresented Yirlvrii'g. 3. The follower19..,is simi.'- lar in Vform to the .follower y2O, whichv .is shown inFig. .5. i

A friction plate 31is located `on the anis .of the gear and in4engagenlent with ,the facesof.the`:blocl sf27, 28,129 and 30 whichare'parallel thereto. The length lof lthe ,plate 31 is less .than thedistance between .the inner faces .of the followers19, v2O, when i the,gear is .expandel, and this ,plateldetermines ,the limit of`compressive ,movement 'lghe range of .this movement may bre-.exs

tended, without `shortening n.the lpl-ate ,31,7 providing ther followerswith vertical re 1w cesses, as shownatl20, .within which )the .ends of`:the plate may enter.

Eachof .the wedgeeblocksiQl .to 26 isilper-y .forated Aon its median-line which istrans- ...verse tothe raxis ofthe gear, and atension rod,as 32, 33 and 34, extends through vfthe apertures Vof each pair ofthesehlocks,` The `plate A31 is slotted inw-ardllv from itsends, ,asshown at 231, l231, `to yaccommodate..fthe rods 32 and l:34 andpermitits free move- ,ment with reference thereto.` Itis Valso cen- Vtrallyapertured, as shown at 131, t'o receive Athe `rod33. This perforationmay :be-of Vvappropgimately Ithe diameter -of the rod, as the twoelements have -n'o vrelative movement.

',Ehe `several rods 32,33 and 34 `are shown as 'of .equal length, andas' extending through openings .110.11.111 the sills 10 and 1,1-` Uponeach v.of these rods :is slowed a pair of spring seats 3.5, located`outside of the sills #but harngwinwardly projecting stoms which :seatagainstrtho outer faces of the wedge-blocks through which jthe nodpasses.` Upon lthe outer, ends iof ,each offthe ,rods is .-meunted ,apair ofsplifng seats v36,.

which ,boar outwardly against Retaining )nuts 3.7 Screwed Lupon the endsof the rod.' A, Helical springs 3,8, .arecmountjedlnponithe .endAloo-.rtons;olf yeach of ,the itensionrods,

reacting between the inner and outer seats 35, 36. In order to secureample spring resistance without employing an excessively heavy spring,an inner helical spring, as 39, may be inclosed within each of thesprings 38.

lVhen the followers i9, 20, are provided with the recesses 120, theirwedge faces may be transversely grooved, as shown at 220, to provideclearance for the adjacent tension rods Vwhen the gear is compressed.The'blocks 27 to 3() are similarly recessed as shown.

When the gear is installed the several springs are placed undersufficient tension to hold all of the cooperating faces of the variousfrictional elements of the gear in contact. The. length of thewedge-blocks 2l to 26, transverse to the avisV of the gear, is such asto permit sufficient outward movement of these blocks, due to thecomplete compression of the gear, without interference with the sillsl0, l1. Thelength of the blocks 27 to 30, transverse to the avis of thegear, may be such that their outer ends are approximately in contactwith the inner faces of the sills when the gear is expanded.

When the gear is compressed, as by a bufling action, the follower 2Oremains at rest against the bufling lugs, the follower 19 is pushedbackwardly, forcing outwardly, by a wedging action, the blocks 2l, 24,against the resistance of the springs 38. These blocks, while slidingupon'the blocks 27, 29, are also moved backwardly, pushing back theblocks 27, 29, which force Aoutwardly and backwardly the blocks 22,

25. The latter blocks similarly act upon the blocks 2S, 30, forcingoutwardly the blocks 23, 26.

In addition to the backward movement of the'blocks 27 to 30, they havean inward 'movement due to the wedging action, which brings them intofrietional engagement Awith the plate 3l. AThe several tension rods movelaterally with the wedge-blocks through which they pass as the latterare carried backwardly, and the friction plate '3l' travels with thecentral rod.

lVhen the gear is relieved from the buffing force, it isrestored to thenormal posi- 'tion of Fig.' l by the expansion of the 'several springsand the consequent inward scribed, differing in action only in that thefrictional engagement of the blocks 4:1, 42, with the follower isincreased. YWhile the range of movement is decreased the capacity may bethe same. In the construction of Fig. l it is entirely feasible toprovide for a compressive movement of four and one-half inches, withoutlenlgthening the gear beyond usual practice, the range of movementdepending upon the pitch of the wedging faces.

As the gear is compressed friction is developed between all of thecontacting faces of the various elements, and the area of these faces issufficient to provide for the absorption of a very large percentage ofthe force applied, but with comparatively,7 little wear of the parts.

rlhe gear may be made at comparatirely low cost, as the cheaper gradesof: metal may be employed and practically no machining is required. Itis of such simple form that it may be easily assembled wilhout theemployment of skilled labor. AFor the same reason repairs andrcplacements may be easily elfecl'ed, and usually without requiring theremoval of the entire geur from the car.

While preferred forms of construction are shown, various changes ofdetail may be made without departing` from the scope of the invention.The number of tension rods and of cooperating parts may be varied.

I claim as my invention:

lQIn Va draft gear, in combination, a follower the inner face of whichis wedgeshaped, a friction plate on the longitudinal median line of thegear and normally out of engagement with the follower, a friction blockbearing against each face of the plate and having a face receding fromthe adjacent wedge face of the follower, a wedge block interposedbetween the named face of the block and such adjacent face of thefollower, spring means for advancing the wedge block, and means forresisting lateral movement of the friction 'block away from the wedgeblock.

-' 2. In a draft gear, in combination, a follower the inner face ofwhich 1s wedge- 'shaped, a friction plaie on the longitudinal medianline of the gear, a friction block bearing against each face of theplate and having a face receding from the adjacent wedge face of thefollower, a wedge block interposed between the named face of the blockand such adjacent face of the follower, spring means for advancjng thewedge block, and means for yieldingly resisting lateral movement of thefriction block away from the wedge block.

3. In a draft gear, 'in combination, a follower the inner face of whichis wedgeshaped, a friction plate on the longitudinal i l gear, a springon cach end portion of the rod and reacting between the adjacent wedgeblock and a head on the rod, and means for resisting lateral movementlofv the friction block away from the wedge block.

4L. In a draft gear, in combination,a follower t-he inner face of whichis wedgeshaped, a friction plate on the longitudinal median line of thegear and normally ont of engagement with .the followcr, a friction blockbearing against each face of the plate and having a face receding fromthe adjacent wedge face of the follower, a wedge block interposedbetween the named face of the block and suchadjacent face of thefollower',` spring means for advancing the wedge block, and wedge meansfor resisting lateral movement of the friction block away from the wedgeblock.

5. In a draft gear, in combination, a follower the inner face of whichis wedgeshaped, a friction plate on the longitudinal median line of thegear, a friction block bearing against each face of the plate and havinga face receding from the adjacent wedge face of the follower,awedge-block interposed between the named face of the block and suchadjacent face of the follower, spring means for advancing thewedgeblocl, wedge means for .resisting lateral movement of the frictionblock away from the wedge-block, and resilient means for` resistingmovement of such wedge means.

6. In a draft gear, in combination, a follower the inner face of whichis wedgeshaped, a friction plate on the longitudinal median line of thegear, a triangular friction block bearing against each face of the plateand having a face receding from the adjacent wedge face of the follower,a wedge block interposed between the named face of the block and suchadjacent face of the follower, spring means for advancing the wedgeblock, a wedge block engaging the third face of each friction block,spring means for advancing the last-named wedge block, and means forresisting lateral movement of such block away from the friction block.

7. In a draft gear in combination` a pair of followers, the inner faceof each being wedge-shaped, a friction p-late located on thelongitudinal median line of the gear and of less length than the normaldistance between the followers, a series of triangular friction blocksengaging each face of theplate, such blocks with the inclined faces ofthe" fol'- lowers forni-ing af succession of surfaces outwardly inclinedfrom the median line ofV the gear,` adjacent surfaces being oppositelyinclined, a series of wedge blocks interposed between adjacent inclinedsurfaces?, rods projecting v through oppositely disposed wedge blocks,and. springs mounted on each end portion of eaclf rod for resistingout-fward movement ofthe wedge blocks associated tlierewith.

8. In a draftfgear, in combination, a 'fol lower the vinner face ofwhich is wedgeshaped, a friction plate on the longitudinal median lineof the gear, a friction blockv bearing against each faceof the plate andhavinga face receding from the adjacent' wedge face of thefollower, rawedge block `interposedl between the named face of the block and suchadj acent face of the follower,v spring means for advancing thewedgebl'oek, means for yieldingly resisting lateral neove-l niegnvt foflthefriction block away from the wedge block, afnd means for maintainingthev friction plate in constant relative relation to the two followers.

9. A pair .of opposed followers, a floating friction plate on thelongitudinal median line of the gear, the length of the plate being lessthan the normal distance between the followers, two sets of friction andwedging elements, one at each end portion of the gear, for cooperatingwith the followers and plate,a pair of wedges interposed between the twosets, a rod extending through the wedges and through a close-fittingapperture in the friction. plate, and springs on the rod urging thewedges inwardly.

10. A draft gear comprising in combination a pair of lug engagingfollowers, a pair of opposed wedge blocks slidingly engaging the innerface of each follower,k the inner face of each block being inclined awayfrom the center line of the gear and from the adjacent follower,friction blocks slidably engaging such inclined faces and complementarythereto, and a friction platev on the longitudinal center line of thegear and j slidably engaging the friction blocks.

1l. A draft gear comprising in combination a pair of lug engagingfollowers the inner face of each being wedgeI shaped, a floatingfriction plate on the center line of the gear and o-f less length thanthe normal distance between the followers, triangular friction blocksslidably engaging the' side faces of the platel and a. wedge blockinterposed between each inclined face of the followers and the adjacentface of a friction block.

12. A draft gear comprising in combination a pair of lug engagingfollowers the inner face of each being wedge shaped, a floating frictionplate on the center line of the gear and of less length thanv the normaldistance between the followers, two pairs of triangular friction blocksengaging opposite sides of the plate, and wedge blocks interposedbetween contiguous faces of the followers and friction blocks and of thefriction blocks of each pair.

13. A draft gear comprising in combina.- tion a pair of lug engagingfollowers, a pair of opposed wedge blocks slidingly engaging the'innerface of each follower, a tension rod extending through the members ofeach pair of wedge blocks trantverse to the axis of the gear, springsmounted on each rod and urging the blocks toward each other, a frictionplate located on the axis of the gear and friction blocks engageablewith each side of the gear and with the wedge blocks, the engaging facesof the wedge and friction blocks being oblique to' the axis of the gear.

14. A draft gear comprising in combination a pair of wedge shapedfollowers7 a floating friction plate located on the axis of the gearbetween the followers and normally out of contact with each, a pair oftriangular friction blocks slidably engaging each side of the plate,three pairs of triangular wedge blocks, one pair thereof beinginterposed between each of the followers and the adjacent frictionblocks and the third pair being interposed between the members of eachpair of friction blocks, a tension rod passing through the members ofeach pair of wedge blocks transverse to the axis of the gear and springsmounted on the end portions of each rod and bearing inwardly on thewedge blocks associated therewith.

15. A draft gear comprising, in combination, a pair of lug engagingfollowers a pair of opposed wedge blocks slidingly engaging the innerface of each follower, the inner face of each block being inclined awayfrom the center line of the gear and from the adjacent follower,friction blocks slidably engaging such inclined-faces and complementarythereto, a friction element on the longitudinal center line of the gearand slidably engaging the friction blocks and means for resilientlyholding the elements in frieti on al engagement.

WALTER H. COTTON.

